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A computational fluid dynamics model for wind simulation:model implementation and experimental validation

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2012年第4期13卷 274-283页

作者： Zhuo-dong ZHANG Ralf WIELAND Matthias REICHE Roger FUNK Carsten HOFFMANN Yong LI Michael SOMMER Institute of Soil Landscape research Leibniz-Centre for Agricultural Landscape Research(ZALF)Muencheberg 15374Germany Institute of Landscape System Analysis Leibniz-Centre for Agricultural Landscape Research(ZALF)Muencheberg 15374Germany Institute of Agricultural Environment and Sustainable Development Chinese Academy of Agricultural Sciences(CAAS)Beijing 100081China Institute of Earth and Environmental Science University of PotsdamPotsdam 14476Germany

To provide physically based wind modelling for wind erosion research at regional scale, a 3D computational fluid dynamics (CFD) wind model was developed. The model was programmed in C language based on the Navier-Stokes equations, and it is freely available as open source. Integrated with the spatial analysis and modelling tool (SAMT), the wind model has convenient input preparation and powerful output visualization. To validate the wind model, a series of experiments was con- ducted in a wind tunnel. A blocking inflow experiment was designed to test the performance of the model on simulation of basic fluid processes. A round obstacle experiment was designed to check if the model could simulate the influences of the obstacle on wind field. Results show that measured and simulated wind fields have high correlations, and the wind model can simulate both the basic processes of the wind and the influences of the obstacle on the wind field. These results show the high reliability of the wind model. A digital elevation model (DEM) of an area (3800 m long and 1700 m wide) in the Xilingele grassland in Inner Mongolia (autonomous region, China) was applied to the model, and a 3D wind field has been successfully generated. The clear imple- mentation of the model and the adequate validation by wind tunnel experiments laid a solid foundation for the prediction and assessment of wind erosion at regional scale.

关键词： Wind model Computational fluid dynamics (CFD) Wind erosion Wind tunnel experiments Spatial analysis andmodelling tool (SAMT) Open source

REGENERATION FACTOR 1, a peptide boost for wound healing and plant biotechnology

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Molecular Plant 2024年第9期17卷 1333-1334页

作者： Andreas Schaller University of Hohenheim Department of Plant Physiology and Biochemistry70593 StuttgartGermany

Plants respond to wounding such as caused by insect herbivores by activating their defenses and thus increasing their resistance against attacking pests and opportunistic pathogens(Howe and Schaller,2008).The phenomenon was first described more than 50 years ago by Green and Ryan,who reported that wounding triggers tomato and potato plants to produce proteinase inhibitors that inhibit digestive proteases in the gut of leaf-eating insects to starve them of nutrients(Green and Ryan,1972).They also observed that the accumulation of proteinase inhibitors is not restricted to wounded leaves but occurs throughout the aerial parts of the *** search for a chemical signal that is released locally in response to wounding and that mediates systemic activation of defense gene expression led to the identification of systemin,the first ever peptide with hormonelike activity in plants(Pearce et al.,1991).These seminal findings sparked much research into systemic defense responses and peptide signaling in general,and we know now that systemin is one of many phytocytokines that regulate a multitude of immune responses in plants(Schilmiller and Howe,2005;Gust et al.,2017).

关键词： wound activation defense

Unraveling the mark of surface defects on a spinterface： The nitronyl nitroxide/TiO2（110） interface

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Nano research 2016年第11期9卷 3515-3527页

作者： Reza Kakavandi Arrigo Calzolari Yulia B. Borozdina Prince Ravat Thomas Chasse Martin Baumgarten M. Benedetta Casu Institute of Physical and Theoretical Chemistry University of Tubingen Auf der Morgenstelle 18 72076 Tubingen Germany CNR-NANO Istituto Nanoscienze Centro S3 41125 Modena Italy Max Planck Institute for Polymer research Ackermannweg 10 55128 Mainz Germany

Metal-free organic radicals are fascinating materials owing to their unique properties. Having a stable magnetic moment coupled to light elements makes these materials central to develop a large variety of applications. We investigated the magnetic spinterface coupling between the surface of a single rutile TiO2（110） crystal and a pyrene-based nitronyl nitroxide radical, using a combination of thickness-dependent X-ray photoelectron spectroscopy and ab initio calculations. The radicals were physisorbed, and their magnetic character was preserved on the （almost） ideal surface. The situation changed completely when the molecules interacted with a surface defect site upon adsorption. In this case, the reactivity of the defect site led to the quenching of the molecular magnetic moment. Our work elucidates the crucial role played by the surface defects and demonstrates that photoemission spectroscopy combined with density functional theory calculations can be used to shed light on the mechanisms governing complex interfaces, such as those between magnetic molecules and metal oxides.

关键词： organic spinterface photoemission spectroscop density functional theory calculations

Genesis and soil environmental implications of intact in-situ rhizoliths in dunes of the Badain Jaran Desert,northwestern China

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Acta Geochimica 2022年第5期41卷 811-822页

作者： Qingfeng Sun Kazem Zamanian Arnaud Huguet Omid Bayat Hong Wang Hanan SBadawy Key Laboratory of Resource Environment and Sustainable Development of Oasis Northwest Normal University730070 LanzhouGansu ProvinceGansuPR China Key Laboratory of Eco-function Polymer Materials of the Ministry of Education Northwest Normal University730070 LanzhouGansuPR China Institute of Soil Science Leibniz University of HannoverHerrenhäuser Straße 230419 HannoverGermany Sorbonne Université CNRSEPHEUMR METISF-75005 ParisPSLFrance Department of Soil Science Isfahan University of Technology84156-83111 IsfahanIran Interdisciplinary research Center of Earth Science Frontier Beijing Normal University100875 BeijingPR China Department of Geology Faculty of ScienceBeni-Suef University62521 Beni-SuefEgypt School of Geographical Sciences Nanjing University of Information Science and Technolog210044NanjingChina

Desert rhizoliths are generally found as weathered,broken and scattered samples on dune field surface,but rarely insitu in their initial states buried under the soil of desert in the Badain Jaran Desert,northwest *** study off ers an assessment of the morphological,mineralogical,and chemical properties of intact and in-situ rhizoliths found in soils of swales and depressions among dune *** characteristics of these rare and precious objects were assessed using optical polarizing microscopy,cathodoluminescence,scanning electronic microscopy,radiocarbon dating,and stable isotopic analyses,providing the opportunity for discussion of the rhizolith formation mechanisms and associated environmental *** and laboratory investigations showed that the in-situ intact rhizoliths were formed only in the places where Artemisia shrubs are living,and the remaining root relicts within rhizoliths belong to this *** spatial distribution of rhizoliths also suggested that low topographic positions on a landscape provided soil moisture,and redox environments favored rhizolith formation.A semi-closed redox environment in the subsoil at swales and depressions,where water is always present,along with the sandy soil texture,facilitated fast water percolation to deeper depths and *** a soil environment not only provides water for Artemisia growth,but also for the weathering of minerals such as felspars and calcite from primary carbonates,and for the decomposition of root ***,harsh climatic conditions,such as strong winds and solar radiation,led to water evaporation through dead root channels and triggered the calcification along the root *** entrapped lithogenic carbonates and to a lesser extent the decomposition of Artemisia roots provided the carbon sources for the rhizoliths formation,while the weathering of soil minerals,particularly feldspars and carbonates,was the main source of *** in the Badain Jaran des

关键词： Rhizoliths Calcification Leptic regosols Artemisia roots Decomposition Soil moisture

POLIII-derived non-coding RNAs acting as scaffolds and decoys

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Journal of Molecular Cell Biology 2019年第10期11卷 880-885页

作者： HendrikTauber Stefan Huttelmaier Marcel Kohn Institute of Molecular Medicine Section for Molecular Cell BiologyFaculty of MedicineMartin Luther University Halle-WittenbergCharles Tan ford Protein CentreKurt-Mothes-Str.3a06120 HalleGermany Julius Bernstein Institute of Physiology Faculty of MedicineMartin Luther University Halle-WittenbergCharles Tan ford Protein CentreKurt-Mothes-Str.3a06120 HalleGermany

A large variety of eukaryotic small structured POLIII-derived non-coding RNAs(ncRNAs)have been described in the ***,for only few,e.g.7SL and H1/MRP families,cellular functions are well *** the vast majority of these transcripts,cellular functions remain *** findings on the role ofY RNAs and other POLIII-derived ncRNAs suggest an evolutionarily conserved function of these ncRNAs in the assembly and function of ribonucleoprotein complexes(RNPs).These RNPs provide cellular‘machineries’,which are essential for guiding the fate and function of a variety of *** this review,we summarize current knowledge on the role of POLIII-derived ncRNAs in the assembly and function of *** propose that these ncRNAs serve as scaffolding factors that‘chaperone’RNA-binding proteins(RBPs)to form functional *** addition or associated with this role,some small ncRNAs act as molecular decoys impairing the RBP-guided control of RNA fate by competing with other RNA *** suggests that POLIII-derived ncRNAs serve essential and conserved roles in the assembly of larger RNPs and thus the control of gene expression by indirectly guiding the fate of mRNAs and IncRNAs.

关键词： ncRNA POLIII RBP scaffold RBP decoy

Chatter prediction for uncertain parameters

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Advances in Manufacturing 2018年第3期6卷 319-333页

作者： Michael Loser Andreas Otto Steffen Ihlenfeidt Günter Radons Institute of Machine Tools and Control Engineering TU Dresden 01069 Dresden Germany Institute of Physics Chemnitz University of Technology09107 Chemnitz Germany

The occurrence of chatter in milling processeswas investigated in this study. The prediction of the sta-bility lobes of metal cutting processes requires a model ofthe cutting force and a model of the dynamic machine toolbehavior. Parameter uncertainties in the models may leadto significant differences between the predicted and mea-sured stability behavior. One approach towards robuststability consists of running a large number of simulationswith a random sample of uncertain parameters and deter-mining the confidence levels for the chatter vibrations,which is a time-consuming task. In this paper, an efficientimplementation of the multi frequency solution and theconstruction of an approximate solution is presented. Theapproximate solution requires the explicit calculation of themulti frequency solution only at a few parameter points,and the approximation error can be kept small. This studyfound that the calculation of the robust stability lobe dia-gram, which is based on the approximate solution, is sig-nificantly more efficient than an explicit calculation at allrandom parameter points. The numerically determinedrobust stability diagrams were in good agreement with theexperimentally determined stability lobes.

关键词： Milling Chatter Uncertainties Vibration Stability

Investigation of coupling effect on the evolution of Richtmyer-Meshkov instability at double heavy square bubbles

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Science China(Physics,Mechanics & Astronomy) 2024年第1期67卷 52-70页

作者： Satyvir Singh Dhouha Taib Jalleli Applied and Computational Mathematics RWTH Aachen UniversityAachen 52056Germany Department of Mathematics Graphic Era Deemed to be UniversityDehradun 244712India Mathematics Department University College in DarbJazan UniversityAbu As Sadad 89653Saudi Arabia

This study investigates numerically the coupling effect on the evolution of Richtmyer-Meshkov instability at double heavy square *** scenarios are considered,each with varying initial separations S/L(where L demotes the side length of the square)ranging from 0.125 to *** are filled with SF6gas,and are enclosed by *** simulations of shock-induced multispecies flow are performed by solving the two-dimensional compressible Euler equations with a higher-order explicit modal discontinuous Galerkin *** simulations demonstrate that the flow morphology resulting from the coupling effect is highly dependent on the separation between two *** the separation is large,the squares experience a weaker coupling effect and evolve ***,as the separation reduces,the coupling effect manifests earlier in the interaction and becomes more *** a result,this phenomenon greatly intensifies the motion of inner upstream/downstream vortex rings towards the symmetry axis,leading to the emergence of multiple jets such as the twisted downward,upward,and coupled jets.A thorough exploration of the coupling effect of double squares is conducted by analyzing the vorticity ***,a significant quantity of vorticity is produced along the squares interface for smaller ***,these coupling effects result in various interface features(upstream/downstream movement,and height/width evolution),and temporal variations of various spatially integrated ***,the analysis of the flow structure also considers the interaction between two more flow parameters,the Mach and Atwood numbers,in order to evaluate the coupling effects.

关键词： RM instability shock wave double square bubbles coupling effect

Growth-Regulating Factors （GRFs）： A Small Transcription Factor Family with Important Functions in Plant Biology

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Molecular Plant 2015年第7期8卷 998-1010页

作者： Mohammad Amin Omidbakhshfard Sebastian Proost Ushio Fujikura Bernd Mueller-Roeber Institute of Biochemistry and Biology University of Potsdam Karl-Liebknecht-Straβe 24-25 Haus 20 14476 Potsdam-Golm Germany Max-Planck Institute of Molecular Plant Physiology Am Muhlenberg 1 14476 Potsdam-Golm Germany

Growth-regulating factors （GRFs） are plant-specific transcription factors that were originally identified for their roles in stem and leaf development, but recent studies highlight them to be similarly important for other central developmental processes including flower and seed formation, root development, and the coordination of growth processes under adverse environmental conditions. The expression of several GRFs is controlled by microRNA miR396, and the GRF-miRNA396 regulatory module appears to be central to several of these processes. In addition, transcription factors upstream of GRFs and miR396 have been discovered, and gradually downstream target genes of GRFs are being unraveled. Here, we review the current knowledge of the biological functions performed by GRFs and survey available molecular data to illustrate how they exert their roles at the cellular level.

关键词： abiotic stress chromatin remodeling flower development growth regulation leaf development,miRNA

Facing different predators： adaptiveness of behavioral and morphological traits under predation

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Current Zoology 2017年第3期63卷 249-257页

作者： Martina HEYNEN Nils BUNNEFELD Jost BORCHERDING Department of General Ecology and Limnology Ecological Field Station Grietherbusch Zoological Institute of the University of Cologne Rees Germany Department of Chemistry Umea University Umea Sweden Department of Ecology and Environmental Sciences Umea University Umea Sweden Department of Life Sciences Biological and Environmental Sciences School of Natural Sciences University of Stirling Stirling UK

Predation is thought to be one of the main structuring forces in animal communities. However, se- lective predation is often measured on isolated traits in response to a single predatory species, but only rarely are selective forces on several traits quantified or even compared between different predators naturally occurring in the same system. In the present study, we therefore measured be- havioral and morphological traits in young-of-the-year Eurasian perch Perca fluviatilis and com- pared their selective values in response to the 2 most common predators, adult perch and pike Esox lucius. Using mixed effects models and model averaging to analyze our data, we quantified and compared the selectivity of the 2 predators on the different morphological and behavioral traits. We found that selection on the behavioral traits was higher than on morphological traits and perch predators preyed overall more selectively than pike predators. Pike tended to positively se- lect shallow bodied and nonvigilant individuals （i.e. individuals not performing predator inspec- tion）. In contrast, perch predators selected mainly for bolder juvenile perch （i.e. individuals spend- ing more time in the open, more active）, which was most important. Our results are to the best of our knowledge the first that analyzed behavioral and morphological adaptations of juvenile perch facing 2 different predation strategies. We found that relative specific predation intensity for the di- vergent traits differed between the predators, providing some additional ideas why juvenile perch display such a high degree of phenotypic plasticity.

关键词： behavior morphological variation Perca f/uviatilis perch pike predator-specific defenses selective predation